Review of experimental and theoretical research on positronium ions and molecules

Electron superhalogens as positronium superhalogens

“…Experimental investigations have confirmed the presence of atomic positronic species, such as PsH, 5 Ps À , and Ps 2 . 6 In addition, approximately 90 molecules containing positrons have been identified. [7][8][9][10] Most experimental evidence for the binding of positrons to molecules has been acquired through the analysis of annihilation rates resolved as functions of the positron energy.…”

“…To gain a more in-depth understanding of this observation, we subtract DE[X À -MX k ] in eqn (6) from DE[X-MX k ] in eqn (5) and consider the expressions of EA[X] and EA[MX k+1 ] from eqn (4) to obtain the expression…”

Lagrange-mesh calculations of P-wave resonances in three-body atomic systems

“…From the pioneering observation of Madden and Codling on resonances in the photoionization of the 1 P o states in helium in 1963 [1] to the more recent measurements on exotic systems [2][3][4][5], resonances in three-body atoms have attracted much scientific interest. In particular, bielectronic systems such as the helium atom and the positronium ion have been the object of growing research (see, for low angular momenta L, the energies and widths reported in [6][7][8][9][10][11][12][13], and the references therein).…”